This invention relates to a method of calcining carbonaceous blocks into carbonaceous bodies, in particular anodes, in either continuous or intermittent operation furnaces, and to a containment structure for implementing the method.
The carbonaceous blocks are generally produced by pressure molding or extruding into a desired shape a carbon-carrying material mixture, such as petroleum coke, anthracite, gas black graphite and the like, with a binder material such as tars and/or pitches. By calcining such blocks the binder is baked to achieve desired mechanical and electric characteristics in the calcined bodies obtained.
Known are methods of calcining anodes in continuous operation furnaces.
Attempts have been made, which provide for the carbonaceous bodies (anodes) to be covered with carbonaceous powder for protection against oxidation, packed in muffles, placed on a cart, and pushed into the furnace in accordance with a preset thermal schedule.
Normally the composition of the carbonaceous powder is similar to the above indicated composition of the carbonaceous blocks but without the binder material.
Such attempts, while affording the advantage of providing carbonaceous bodies in a continuous cycle, have some drawbacks which this invention is directed to obviate.
One of these drawbacks is a high fuel consumption, resulting from the need for heating, together with the carbonaceous bodies, also a large body of carbonaceous powder covering them.
Another drawback is the time required for the operation of covering the anode with carbonaceous powder at the beginning of each cycle, and for removing the carbonaceous powder at the end of each cycle.
A further drawback originates from that, during calcination, the anodes are distorted and cracked owing to their contacting, either directly or indirectly through the carbonaceous powder, the cart walls.